atmel_lcdfb: fix pixclock divider calculation

Fix divider calculation and allow CLKVAL = 0 (divisor 2)

It was not possible to get the clock value 0 (divisor 2) because
the test "<=0" force the BYPASS bit to be activated instead.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Cc: Per Hedblom <per.hedblom@abem.se>
Cc: Roel Kluin <12o3l@tiscali.nl>
Cc: Jan Weber <jw022609@uni-greifswald.de>
Cc: Andrew Victor <linux@maxim.org.za>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 6 insertions, 5 deletions

diff --git a/drivers/video/atmel_lcdfb.c b/drivers/video/atmel_lcdfb.c
index 8ffdf3578768..b004036d4087 100644
--- a/drivers/video/atmel_lcdfb.c
+++ b/drivers/video/atmel_lcdfb.c
@@ -441,14 +441,15 @@ static int atmel_lcdfb_set_par(struct fb_info *info)
 
         value = DIV_ROUND_UP(clk_value_khz, PICOS2KHZ(info->var.pixclock));
 
-        value = (value / 2) - 1;
-        dev_dbg(info->device, "  * programming CLKVAL = 0x%08lx\n", value);
-
-        if (value <= 0) {
+        if (value < 2) {
                 dev_notice(info->device, "Bypassing pixel clock divider\n");
                 lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, ATMEL_LCDC_BYPASS);
         } else {
-                lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1, value << ATMEL_LCDC_CLKVAL_OFFSET);
+                value = (value / 2) - 1;
+                dev_dbg(info->device, "  * programming CLKVAL = 0x%08lx\n",
+                                value);
+                lcdc_writel(sinfo, ATMEL_LCDC_LCDCON1,
+                                value << ATMEL_LCDC_CLKVAL_OFFSET);
                 info->var.pixclock = KHZ2PICOS(clk_value_khz / (2 * (value + 1)));
                 dev_dbg(info->device, "  updated pixclk:     %lu KHz\n",
                                         PICOS2KHZ(info->var.pixclock));